package com.ldx;

/**
 * @author lidexin
 * @create 2021-09-20 14:40
 */

/**
 * 线程之间的通信问题，生产者和消费者问题，等待唤醒，通知唤醒
 * 线程交替执行A B 操作同一个变量 num = 0
 * A num + 1
 * B num - 1
 */
public class A {
    public static void main(String[] args) {
        Data data = new Data();
        new Thread(()-> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();

        new Thread(()-> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();

        new Thread(()-> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"C").start();

        new Thread(()-> {
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"D").start();
    }
}

//判断等待，业务，通知
class   Data{ //数字 资源类
    private int number = 0;

    //+1
    public synchronized void increment() throws InterruptedException {
        while (number!=0) {
            //等待
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程，我+1完毕了
        this.notifyAll();
    }

    //-1
    public synchronized void decrement() throws InterruptedException {
        while (number==0) {
            //等待
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程我-1完毕了
        this.notifyAll();
    }
}
